The Study Of Genetic Structure Of Population Of Common Wild Rice O.Rufipogon Griff. In Sanya And Qionghai

We studied the genetic structure of two populations of common wild rice O. rufipogon Griff from Sanya city and Qionghai city in Hainan using 37 SSR markers. 107 alleles were detected in the 37 SSR loci, 3 alleles for one locus on average. SSRs have more genetic variability in Sanya population than in Qionghai population. The percentage of SSR loci polymorphic is 91.8919% in Sanya population and 81.0811% in Qionghai population. The value of direct count heterozygosity is 0.5651 in Sanya population, 0.4079 in Qionghai population; the value of expect heterozygosity is 0.4449 in Sanya population, 0.2057 in Qionghai population; the value of unbiased heterozygosity is 0.4661 in Sanya population, 0.2627 in Qionghai population. There are moderate genetic differences between Sanya and Qionghai populations with FST=0.3909 indicating that 60.91% of the total genetic variation exists within populations. The value of fixation index is -0.2124 in Sanya population, -0.5527 in Qionghai population, and the rate of outcross in Sanya population is 1.5394, 3.2349 in Qionghai population, which show that the populations have an excess of heterozygotes and the inbreeding doesn't occur within the populations. FIS, one of the Wright's F-statistics elements also shows that an excess of heterozygotes exits within populations, FIS=-0.3587, but FIT, another of Wright's F-statistics elements, shows that an deficiency of heterozygotes exists within two population as one whole, FIT=0.1730. The result of x2 test shows that the observed frequency of genotypes at 15 SSR loci in Sanya population significantly deviates from that under Hardy-Weinberg proportion at 0.05,0.01,0.001 levels, and that of 19 SSR loci is consistent with Hardy-Weinberg proportions, otherwise, in Qionghai population, the observed frequency of genotypes at 11 SSR loci deviates from Hardy-Weinberg proportions at 0.05,0.01,0.001 levels and the observed frequency of genotypes at another 17 SSR loci is consistent with the Hardy-Weinberg propotions. Nm between two populations is 0.3895based on the FST (e. g. there are 0.3895 common wild rices exchanged between Sanya and Qionghai populations per generation) . And genetic distance between the populations is 0.4486 based on Nei's(1972) genetic distance formula. Using Nei's(1972) genetic distance formula and UPGMA (Unweighted pair-group method with arithmetic mean), We studied the genetic relationship among Indica , Japonica, Sanya and Qionghai common wild rice, 7 pieces of other wild rice, and found that the common wild rice in Sanya and Qionghai show more closed relationship with Indica than with Japonica.